Land & Sea’s DYNOmite AC, Eddy-Current (air or liquid cooled) and Water-Brake Absorber units are also available as separate components.

“Do you have a custom dynamometer application? We manufacture a
full line of absorbers (and controls) in-house – so give us a call!”

For customers building their own systems, DYNOmite absorbers offer an affordable way to build your own state-of-the-art,
industrial-duty engine or chassis dynamometer. We also offer hybrid systems that can combine the response of AC units with
the cost-effective power capacity of water-cooled absorbers.

AC (Alternating Current) Absorbers

AC
(Alternating Current) Absorbers
deliver the ultimate in electronic load control. Besides offering
load-control response times measured in microseconds and low
inertia, they are capable of providing full-torque loading down to
zero RPM (allowing stall-testing air or electric motors). Moderate
power applications are configured to dissipate their energy into
larger external resistive load banks, while for very low power
testing, heat dissipation can sometimes be handled by the drive’s
internal braking resistors. For applications, in the 200 Hp to
1,250+ Hp range, a regeneration system sends power back into the
utility’s grid (for a credit against the user’s electric bill).

Motoring Mode
is optionally configurable for any of our AC dyno
applications. Only AC absorbers can do double-duty to “motor” your test
engine. In addition to its providing a convenient way to start up the
engine, motoring allows testing its internal frictional cranking loads
on engine dynamometers or simulate down-hill coasting for road-load
dynamometer simulations.

Air-Cooled Eddy-Current Absorbers

Air-Cooled Eddy Current Absorbers offer load-control response
times measured in milliseconds, moderate inertia, and high specific
load capacity – especially in the lower RPM working ranges of most
industrial-type engines. For applications that do not require stall
speed loading, an air-cooled eddy-current absorber is usually the
most cost-effective electric absorber. Their self-cooled rotors
require no external water supply or resistor banks. They also cost
less than planetary-driven water brakes and allow far more design
flexibility than hydraulic pumps.

3" to 30" Diameter Rotors
for loads from under ¼ to over 3,000 foot-pounds. Higher capacities
are available from tandem absorbers or via our overdrive systems.
Installation options include compact integral PTO drive or trunnion
mounting – with direct or belt driven shaft drive.

12-volt DC, 120-volt or 240-volt AC (input) power supply/controls
are available to provide 12, 96 or 192-volt DC PWM (pulse width
modulated) output – which is suitable for many DYNOmite or third
party absorber models. Loading when using these controls is
adjustable – either manually (using either its panel knob or the
built-in 0-10 volt analog control input) or automatically via
digital PID output leads from the DYNOmite data-acquisition
computer. Panel circuit breakers are matched to the customer’s
application, protecting the absorber’s windings.

Liquid-Cooled Eddy-Current Absorbers

Liquid-Cooled Eddy-Current Absorbers offer load-control response
times measured in milliseconds, very-low rotating inertia, and
compact high-specific load capacity. Compared to water-brake
absorbers, they are especially well suited for applications that
require plenty of low RPM torque capacity - as do many
industrial-type engines. For applications which do not require
motoring or stall-speed (zero RPM) loading, our liquid -cooled eddy
current absorbers offer more cost-effective loading than equivalent
capacity AC absorber (motor) and drive can. For applications that
demand high RPM limits, lower system inertia, and continuous-duty
(temperature independence) water-cooled eddy-current absorbers are
the ideal solution.

We manufacture these absorbers
in both single and multi-rotor configurations, in a number of
diameter ranges to cover testing everything from tiny 20,000 RPM two
-stokes to 1,200 Hp diesels. Rotors are added to increase power
capacity, without limiting peak RPM, while rotor diameter is
increased for boosting low-RPM torque capacity. Since we manufacture
these units in-house, we machine and balance the rotors for the
application, wind custom voltage coils, and assemble the ideal
stack-up to get the just the load curve you need. Their modular
design also allows for the possibility of upgrading capacity if your
test engine's increase in size someday.

Planetary-Driven Absorbers

Planetary-Driven Absorbers
compactly couple the high-power
absorption characteristics of water brakes to the high-torque
requirements of low-rpm axle-shaft testing. These are some of the
earliest high-capacity hub-mounted dynamometers. Our custom built,
toroidal-flow units are available in capacities to over 2,000 HP
(per axle). Because they are packed in billet-aluminum housings, it
is still possible for one man to lift and mount the units.

Load control
is done via either a manual control valve or with any
of our larger capacity electronic auto-load servos. These systems
use the same line of load valves as all of our other large
water-brake absorbers. (See the Water-Brake Absorbers section
below for more details.) *

Water-Brake Absorbers

Water-Brake Absorbers
are the first choice when low cost,
ultra-low inertia, high rpm limits, and race engine horsepower
capacity are all requirements. These have been the favorite of
professional automotive engine builders for decades. Water brakes
are similar to centrifugal water pumps. Load is controlled by
varying the volume of water recirculating within the brake with
adjustable inlet and/or outlet valves and orifices. It converts your
engine's power output into "instant hot water."

Power capacity versus size
of a water brake is impressive. An 8
pound absorber handles over 65 continuous Hp at 12,000 RPM. By
comparison, a 300 pound air-cooled eddy-current absorber (with the
same continuous power rating) is only good to 7,000 rpm. It is no
wonder that water brakes are virtually the only choice for testing
2,000+ horsepower drag car engines. Modern water brakes (like the
one pictured at left) boast low enough weight and inertia that they
can be directly mounted on the kart engine's output shaft. Direct
mounting eliminates the inertia and parasitic drag of driveshafts,
u-joints, pillow block bearing, etc.

Manual or automatic control options
allow RPM and load adjustment
via either an operator twisting a valve knob or a computer with an
electronic PID servo. While manual-valve control is not as quick or
precise as the electronic option, it is an inexpensive place to
start – and is easy to upgrade and needs or budgets allow. We even
offer
do-it-yourself plans to help you build everything from the test
stand to a whole dynamometer cell.

Custom hybrid configurations
can can also be designed using a
combination of both an electronic, typically AC, absorber (for fast
torque control) and a large water brake (for inexpensively adding
very-high test power capacity). Control of the pair is handled via
DYNO-MAX “Pro.” While their complexity is typically only justified
for some sophisticated high-output applications, hybrids make it
possible to cost effectively build lower inertia and faster response
dynamometers, (with motoring capabilities) than can be had using any
single braking technology alone.

Need repairs on an old absorber?
As a manufacturer of dynamometer
absorbers and controls, we can often repair otherwise obsolete
units. L&S does everything, from modernizing electronic power
supplies or water-valve controllers to custom winding replacement
coils for “Brand-X” dynamometers.

Call for immediate assistance
in developing your own unique testing
solution - or e-mail
tech@land-and-sea.com for a prompt response.
*Approximate; continuous capacities depend on selected absorber and test speed.
Air-cooled absorber loads are rotor temperature dependent. Water brake power
capacities are RPM dependent and assume a minimum water supply of 1 gpm @ 30 to 60 psi
for every 20 continuous Hp. Call Land & Sea, Inc. at (603) 226-3966 for the
approximate capacity of any specific test configuration.